Study of antinociceptive effect of paroxetine in acute pain in albino rats

Yatish B., Nadia Nausheen, Venkatesh M. Patil

Abstract

Background: Pain is an unpleasant sensory and emotional experience associated with actual or potential tissue damage or described in terms of such damage. In spite of having a number of drugs like NSAIDS and opioids for the management of pain, there is still need for an ideal analgesic agent with favourable safety profile. Many studies have shown that antidepressant drugs also have analgesic activity and particularly, selective serotonin reuptake inhibitors (SSRI) are effective in mixed and chronic pain. This study was done to evaluate antinociceptive effect of Paroxetine in albino rat and to compare antinociceptive effect of Paroxetine with the standard drug pentazocine in albino rat.

Methods: Animals were divided into five groups of six each, group I as control, group II as standard whereas groups III, IV and V as test groups (three doses). Antinociceptive effect of group II pentazocine (10 mg/kg intraperitoneal) and group III, IV and V received paroxetine (2.5 mg/kg, 5 mg/kg, and 10 mg/kg bodyweight intraperitoneally respectively) was evaluated in adult albino rats by Tail flick method.

Results: Mean RT after 120 minutes of injection of Paroxetine (10 mg) was higher than baseline value of 3.42 second with, mean difference 9.55±0.45 and is significant when compared to control. No significant difference in RT was found between paroxetine 10 mg and pentazocine 10 mg. No significant difference found when baseline reading was compared with 120 minutes readings of paroxetine 2.5 group.

Conclusions: Paroxetine, a SSRI antidepressant, has a clear antinociceptive activity.